Hello Timo, thank you for the reply. I was suspecting the same. However:
- the machine runs under Vmware,
- I've tried 3 different kernel versions,
- I've tried 3 different SCSI controllers.
All same results.
On Wed, Dec 21, 2011 at 6:16 PM, Timo Sirainen tss@iki.fi wrote:
On 21.12.2011, at 18.38, hydra wrote:
I suspect, that dovecot v2.0.16 under Linux (tested on Gentoo 3.0.4 Hardened, Gentoo 3.0.6, Gentoo 3.1.4) causes 100% cpu utilization when index.cache is broken and doveadm is lanched. Dovecot uses LDAP as the userdb and provides IMAP and LDA. Because each user has a quota, the doveadm's expunge functionality is used to get rid of old trashed mail.
The mail log: Dec 12 07:38:59 www dovecot: imap(user): Error: Corrupted index cache file /var/data/mail/domain.tld/user/mail/dovecot.index.cache: invalid record size
OK..
Mail is stored on ext4 and flush will use all of the CPU capacity like this: load average: 4.00, 4.01, 4.05
ps: root 26401 98.2 0.0 0 0 ? R Dec20 1369:49 [flush-253:1]
That's a kernel process..
I suspect, that this is something to do with Dovecot, because after deleting the dovecot.index.cache file, everything went back to normal. When this happens, I cannot unmount the drive nor a system reboot works.
That's a kernel bug..
I think you're thinking it the wrong way: Dovecot isn't causing your system to break. Your system is causing Dovecot to break. Faulty hardware or faulty kernel.